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Hepatitis C virus‐specific CD8+ T cell frequencies are associated with the responses of pegylated interferon‐α and ribavirin combination therapy in patients with chronic hepatitis C virus infection
Author(s) -
Tatsumi Tomohide,
Takehara Tetsuo,
Miyagi Takuya,
Nakazuru Shoichi,
Mita Eiji,
Kanto Tatsuya,
Hiramatsu Naoki,
Hayashi Norio
Publication year - 2011
Publication title -
hepatology research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.123
H-Index - 75
eISSN - 1872-034X
pISSN - 1386-6346
DOI - 10.1111/j.1872-034x.2010.00734.x
Subject(s) - ribavirin , medicine , elispot , hepatitis c virus , ns3 , pegylated interferon , cytotoxic t cell , immunology , cd8 , combination therapy , hepatitis c , virology , interferon , virus , immune system , biology , in vitro , biochemistry
Aim: Hepatitis C virus (HCV)‐specific cytotoxic T lymphocytes (CTLs) play critical roles in elimination of the HCV‐infected hepatocytes. However, the mechanism of HCV elimination by pegylated interferon‐α (peg‐IFNα) plus ribavirin is not fully understood. We examined HCV‐specific CTL responses during this combination therapy. Methods: CD8+ T cells were isolated from 16 HCV infected patients treated by this combination therapy and were subjected to IFN‐γ enzyme‐linked immunospot (ELISPOT) assay. Results: The numbers of IFN‐γ spots against HCV Core or NS3 protein‐derived peptides in HCV patients before treatment were similar to those in healthy donors, and those in HCV patients significantly increased 4 weeks after the initiation of combination therapy. All HCV Core or NS3 proteins‐derived peptides specific CD8+ T cells responses in pre‐treated patients were not associated with ALT levels and HCV viral loads of HCV patients before treatment. And those in pre‐treated patients were similar between sustained virologic responder (SVR) patients and non‐SVR patients. Significant increase of HCV Core or NS3 proteins‐derived peptides specific CD8+ T cells responses between before and 4 weeks after this combination therapy were observed in SVR patients, but not in non‐SVR patients. Conclusions: These results demonstrated that significant increase of HCV‐specific CD8+ T cells at 4 weeks after the initiation of IFN treatment might be associated with the elimination of HCV. Our findings suggest that the reactivity against HCV Core and NS3 proteins‐derived peptides might be useful in predicting the clinical outcome of the combination therapy of peg‐IFNα and ribavirin.